In recent years, Sustainability Coordinator Sonia Marcus has fielded questions about steps employees can take to benefit the environment and university budget. In response, the Office of Sustainability has launched an energy Q&A on its Web site. The site addresses some of the most common questions relating to campus energy usage -- and a few questions you may not have thought of.

Does turning my computer on and off use more energy than leaving it on?

Computers require a small surge of power to start up but this amount is far less than the power a computer consumes when fully operating for more than three minutes. The average desktop uses 65-250 watts of power and the typical laptop uses about 15-45 watts. The U.S. Department of Energy recommends turning off your monitor if you won't be using your computer in the next 20 minutes and to shut down the entire system if you're not going to use it in the next two hours. But with modern computers equipped to handle 40,000 on/off cycles, it wouldn't hurt to shut down your computer more often.

Should I turn off my lights when I leave the room for only a few minutes?

Incandescent light bulbs are inefficient and only use 10-15% of the energy they consume to create light. The rest is lost to heat, so incandescents should always be turned off when not in use. Fluorescents (including CFLs) are more sensitive to being turned on and off frequently and should be switched off only if you're leaving the room for longer than 15 minutes. Fluorescent light bulbs require an initial rush of current that uses more energy than leaving lights on for a few minutes, so it's actually more cost and energy efficient to leave them on if you will be returning to a room within the next fifteen minutes.

You can also change your incandescent light bulbs to compact-fluorescent light bulbs (CFLs) which use only one-fourth the energy and lasts up to 10 times longer (five years, on average) than regular bulbs. That's about $30 worth of electricity that doesn't need to be produced or purchased.

Is it worth unplugging appliances or is turning them off just as good?

Many appliances continue using energy even when turned off or on standby. This includes computers, televisions, kitchen appliances, stereos, battery chargers, and any device with a clock, sensor, or lighted display. Five percent of the energy we use in the United States is consumed by appliances that are on standby.

A plugged-in laser printer will consume 113 kilowatt-hours of energy each year at an annual price of $5.36 at Ohio U's current electricity rate of $0.04743 per kilowatt-hour. Each computer will cost $14.75 for the 311 kilowatt-hours it consumes in passive standby mode and microwaves will eat up 35 kilowatt-hours of energy at a price of $1.66 apiece.